Now, polyarylene sulfide is a representative engineering plastic, and the demand for the products being used in a high temperature and corrosive environment or the electronic goods is increasing due to its high heat resistance and chemical resistance, flame resistance, electric insulation, and so on.
Among the polyarylene sulfides, polyphenylene sulfide (PPS) is one and only commercially on sale now. The commercial preparation process of PPS being applicable until now is the method of carrying out a solution polymerization of p-dichlorobenzene (pDCB) and sodium sulfide in a polar organic solvent such as N-methylpyrrolidone. The method is known as Macallum process.
However, when the polyarylene sulfide is prepared by the Macallum process of such solution polymerization type, a salt type by-product may be formed in a solution polymerization process using sodium sulfide, and thus there is a disadvantage of requiring a washing or drying process for eliminating a salt type by-product or a residual organic solvent. Furthermore, since the polyarylene sulfide prepared by such Macallum process has a powder form, the post processability and workability may decrease. Moreover, in the case of the polyarylene sulfide prepared by the Macallum process, the polyarylene sulfide includes a considerable amount of oligomer type polymer chains having low molecular weight, and thus there is a problem of that the processability decreases because a considerable amount of flash occurred when forming an article requiring high degree of precision and a separate process was required for eliminating the same.
Accordingly, a method of melt-polymerizing a reactant including diiodoaromatic compounds and sulfur element was suggested as the method of preparing the polyarylene sulfide such as PPS and the like. Such method does not form a salt type by-product and not use an organic solvent in the preparation process of the polyarylene sulfide, and thus it does not require an additional process for eliminating them. Furthermore, since the polyarylene sulfide prepared finally has a pellet form, there is an advantage of easy post processability and good workability.
However, in the case of the polyarylene sulfide prepared by the melt-polymerization method, the ends of the main chain were composed of iodine and most aryl groups (representatively, benzene). Therefore, there was a disadvantage of that such polyarylene sulfide was inferior in the compatibility with other polymer materials or all sorts of reinforcements or fillers like glass fiber and the like due to the characteristics of its main chain structure.
Due to this, it was hard to compound the polyarylene sulfide prepared by the melt-polymerization method with other polymer materials or fillers for securing optimized properties suitable to various uses, and it was difficult to show optimized properties even if it was compounded with them. Due to such problem, in the case of prior known polyarylene sulfide resin composition, it was true that it was difficult to exhibit sufficient properties suitable for the use and the applications for various uses were limited.
And, it has been continuously required to develop a polyarylene sulfide showing reduced flash occurrence and more excellent processability when it is intended to prepare an article requiring high degree of precision.